Conclusions

This case describes an atypical presentation of SCAR27 associated with a novel nonsense mutation in the GDAP2 gene. Unlike most reported cases where gait ataxia and cerebellar atrophy dominate the clinical picture, this patient exhibited progressive dysarthria as the earliest and most disabling symptom. In contrast, gait disturbance remained mild, and neuroimaging showed no significant abnormalities. Such a presentation expands the phenotypic spectrum of GDAP2-related disorders and highlights the variability in disease expression. The identification of the c.475C>T (p. Gln159*) mutation, previously unreported in the literature, reinforces the role of next-generation sequencing in uncovering rare hereditary ataxias when conventional investigations are inconclusive. Genetic confirmation not only provides diagnostic certainty but also guides counseling regarding prognosis, inheritance, and recurrence risks. This case emphasizes the importance of considering hereditary ataxias in the differential diagnosis of unexplained progressive dysarthria. It demonstrates how careful clinical evaluation combined with genomic testing can advance diagnostic accuracy, inform patient care, and contribute to broader research efforts.